[D-Arg1, D-Trp5,7,9, Leu11]-Substance P

[D-Arg1, D-Trp5,7,9, Leu11]-Substance P is a potent inhibitor of small cell lung cancer (SCLC) cell growth. As a neuropeptide antagonist, [D-Arg1, D-Trp5,7,9, Leu11]-Substance P effectively blocks colony formation stimulated by multiple neuropeptides such as vasopressin and bradykinin. It inhibits Ca2+ mobilization and mitogen-activated protein kinase activation induced by vasopressin or bradykinin. [D-Arg1, D-Trp5,7,9, Leu11]-Substance P also suppresses the growth of H-69 xenografts in nude mice.